Compressor



C'. R. LYON coMPREssoR Filed Marfl 4; *1938 Fig. 23 v Aug. 15, 1939.4

om? @'v f INVENTOR MAI@ ATTORNEY Aug. l15. 1939. G. RqLYN f 2,169,801-

- coMlREssR l Filed March 4.1958 z'sneets-sheet 2 INVEN TOR ATTORNEYPatented Aug. 1s, 1939 zusam compassion George, n. man, Highland Para,nach.

Application March ,4, 1938, Serial No. '193,986

.. i 5 claims. (ci zat-reo) This invention relates to an improvementl inpumps and more especially, pumps for pumping liquids and compressinggases in which two pistons operate in a single cylinder.

. 1 One of the objects of this'v "invention is the provision of a pumpfunctioning without valves in which-'opposed pistons operating in vasingle cylinder control the supply andl distribution of the iluidhandled.

l A secondobject of this invention'is the provision of a pump of thetype set forth in the preceding paragraph ln which the opposed pistonsare actuated by rods from cranks which op'- l erate at the same speedand have dillerent V throws'. v

It is another object `of the present invention to regulate the speedsand paths oi travel of the opposed pistons in relation toeach other andin coordination with respect to the inlet and outlet ports,v whereby theoptimum displacement is achieved and the two pistons are prevented frominterfering with one another.

A further object of this invention i's the provision of a pump of thetype set forth in the pre- :5 ceding paragraphs, which, because of itssimplicity of design, is capable ofv a wide rang of uses yin the pumpand compression iield.

Additional objects and advantages of this invention .will be moreapparent as the description ,0, proceeds, wherein, 4

Figure 1 is a horizontal sectional view of a pump takenalong the lineI-l of Figure 2.

Figure 2 is a sectional elevational view taken along line 2 2 of Figure1.

5 Figure 3 ls a diagram showing one complete cycle of the operation ofthe pump.

Figure 4 is a sectional plan view of a modication of the pump shown inFigures 1 and 2.

Figure 5 is a sectional side elevational view of 0 the modifiedstructure taken cn lines 5 5 ,of

Figure 4.

Figure 6 is a curve showing a characteristic cycle of thepiston-functioning of the modication shown by Figures 4 and4 5 Withreference to Figures 1 to 3, there is shown a cylinder I0 having thereinan inlet port II and a discharge port I2. Located within this cylinderare opposed pistons I3 and It connected to cranks I5 and I6 by rods Iland I8. Crank II is pro- 3 vided with means for receiving suitablemotivating power and this motion istransmitted to crank I5 by means ofside cranks I9, 20, 2l, and 22, `which are connected by links 23 and 24,hereinafter more fully described.

i With special reference to Figure 3, the operation ol' the pump is asfollows: In this ligure, four sets of numerals from 0 to 35 have beenset out.v Those numerals below X-X represent the different positions ofpiston I6 and the set above line X-X represent the different positionsof 5l piston I3. Thus, by comparison of similar numerals, the relativelocation of the pistons and the relative location of the' cranks may beaccurately determined and compared, throughout the cycle. The adjoiningfaces of the pistons are 1I)y in essential contact when the movements ofthe pistons are in the direction from the discharge port I2 towardsthelnlet port II, as shown by O--O in Figure 3. At this point piston I3covers and closes the discharge port l2.' With continued ld movement ofthe pistons toward the inlet port I l, the velocity of the piston Itaccelerates more rapidly than that of piston i3 because` of the relativeposition of the crank centers 25 and 26 in their rotative paths andbecause of the dii- 20 `ference between the lengths of the cranks I5 andI5. Thus, depressed pressure of partial vacuum is created between thepistons. With continued movement, separation of the pistons increasesand at the passage ci piston i4 over the inlet 25 i port II,as as l0,(below X-Xlof Figure 3, the uidfrom the inlet connection will be causedto flow into the space between the pistons. 'I'he pistons 'continue toseparate with the inlet port vII `open, piston i3 then reaching the endof its 80 stroke and reversing its direction as at Il (above X-X) ofFigure 3, followed by the same action on the part kof piston It as at I5(below X-X) of Figure 3. The rate of separation of the pistons thengradually decreases until they 'momentarily 35 attain equal velocity atthe point at which piston I8 completely closes inlet port Il in itsreturn stroke, as at point 2l) (below X-X) of Figure 3. The spacebetween the pistons then decreases as bothtravel towardthe dischargeportl l2, com- 40 pressing the contents of the cylinder.

With continued movement of piston I3, the discharge port is opened, asat point 22 (abov y X-X) of Figure 3. As piston I3 reverses at the endof its travel beyond the discharge port, piston Il' continues toapproach that port which it partially covers and then reverses, as atpoint 35 (below X-X) of Figure 3. Piston I3 overtakes piston VI4 just asthe velocities become equalized momentarily, which is at the point wherepiston I3 covers the discharge port and thus completely ejects thecontents of the space between the pistons and completes 'the cycle.

With additional reference to Figures 1, 2, and 3, more in detail, itwill be seen that cylinder at the end of cylinder I0.

I0 has an inner wall 21 and an outer wall 28 and located between arechambers 28 for circulation of lal suitable cooling medium. The cylinderis also provided with annular spaces 38 and 3|, therein communicating.with the interior of the cylinder by means ofinlet and discharge portsIl and I2. Although not shown, it is to be 4understood that suitableconnections extend ing from the source of supply and point of deliverywill be provided at the exterior openings of inlet and discharge annularspaces 30 and 3|. Secured to the piston I4 by means of .wrist pin 34 isthe forward portion of rod I8. The rearward portion of rod I8 isconnected to crank IB b'y bearing cap 32. Rod I1 has its forward portionconnected to piston I3 through the medium of wrist pin 33 and therearward portion of this rod is connected to crankV I5'by bearing cap35.v

Cranks |5 and I6 have their ends 52. 53, 54, and 55 seated in bearings62, 63,54, and 85, formed It will be noticed that crank I 8 has agreater depth than crank I5 and as herein shownthe diameter of circle oftravel of crank I8 is approximately one third' greaterthan th circle oftravel of crank I5. This is done to impart a greater throw to piston I4than to piston I3 and makes the path of travel of piston I4 alsoapproximately one third farther than the path of travel of piston I3.AIn addition to the difference of the diameter of the path of. travelbetween cranks I5 and I6, there is an additional difference 1 in thatcrank I6 is also provided with a gear wheel 38 which is connected tosuitable motivating power. i

At the end 5210i crank I8 there is provided a side crank 40 and at theend of 53 of crank I5, is provided a side crank 4 I. 'I'hese two sidecranks are connected to each other by link 23. The opposite ends 54 and55 of cranks I5 and I6 are also provided with side cranks 42 and 43which in turn are connected by link 24. 'I'hese side cranks arepositioned so that those on one side will be ninety degrees in advanceof those on the opposite side,

-thus causing delivery of uniform turning effort from crank shaft I6 tocrank shaft I5, and rotation of the two crank shafts is positivelysynchronized. It will, of course be understood in 'this connection thatI do not desire to-limit myself to the particular driving means, to wit,side,

- cranks and links hereinl disclosed. Obviously,

other commercially known means for. synchronizing rotation of crankshafts are usable without departing from the scope of my invention.

If desired, the lubrication of my pump may be accomplished by severalwell known means of lubrication, for example, pressure lubrication byoil lines through the moving parts, with connections to external sourceof oil supply and outlets into the various bearings.

, With reference to the modified structure shown in Figures 4 to 6, itwill be seen that cylinder |0a is provided with an inlet port IIa andadischarge port I2a las well as pistons I3a and I4a. Piston |40, isconnected to crank ISa by rod l8a and piston I3a is connected torocker-shaftv by rod I'Ia. Portions 45 and 48 of crank shaft I 8a areseated in bearings 62a and 63a and rocker -shaft 44 has portions 41 and48 seated in 63a and .64a.

motivating power.u Motion is imparted to rocker shaft 44 by means ofside crank 48 on crank shaft Ilia through link 50 to rocker arm 5I onrocker shaft 44, thereby causing rocker shaft 44 to operate with areciprocating action.

The operation of this modified structure is essentially the same as thatof Figures 1 to 3, ex-

v cept that by means of this construction it is posvof .the arcs throughwhich both crank arms of the rocker shaft travel, thus retarding oraccelerating th'e 'motion bf' the piston driven from the rocker shaftwithrelation to the motion of the crankdriven piston during the variousfunctions of the cycle.

Thus, when the device is used as a compressor,

piston' I3a may be caused to follow closely the motion of piston |4aduring the first part of the cyclefthus minimizing vacuum effect priorto opening of the inlet port, and retarding the motion of piston I3a onthe return stroke following closure of the inlet port, therebypermitting compression of the contents of the inter-piston space to 0rnear the desired delivery pressure before opening of the discharge port.

Figure 6 is a representation of typical variations of inter-piston spaceduring one complete cycle of operation ina machine of the modifiedconstruction (Figures 4 and 5), in'which, however, the coordination ofpiston movements with relation to the inlet and discharge ports issimilar to that characteristic of the two-crank construction (Figures 1and 2). In the diagram (Figure 6) the vertical scale` indicates theface-to-face separation of the twoI pistons in percentage of ualseparation of the pistons to point II where the long-stroke pistonuncovers the inlet port; continued separation to point 2|, where thelongstroke piston covers and closes the inlet port; relative approach ofthe pistons to point 24, where the short-stroke piston uncovers andopens the discharge port; and continued reduction of interpiston spaceduring the remainder of the cycle, in which the material between thepistons is ejected through the discharge port, this action beingcompleted at point 36, when the shortstroke piston covers and closes thedischarge port, with the pistons again in virtual contact, moving in thesame direction at momentarily uniform velocity. v

This feature of complete delivery of the contents of the cylinder is adistinct improvement in the art of gas compression and vacuum pumping ofmechanical accuracy.

What I claim as my invention is:

.1. A pump having a cylinder provided with inlet and outlet ports, twoopposed pistons reciprocably mounted in the cylinder and controllingsaid ports,.m'ea.ns for driving said pistons to -eifect differentialmovement of the pistons in a manner to increase the space therebetweenwhen the fluid, and discharge the same through the outlet port, and saidmeans comprising cranks having diierent throws and respectivelyoperatively connected to the pistons and means for driving the cranks atthe same speed.

2. A lpump having a cylinderprovided with in. let and outlet ports, twoopposed pistons recipro- 'cably mounted in the cylinder and controllingto increase the space therebetween when the inlet port is open to drawiiuid into the cylinder between the pistons and` to eiect movement ofthe pistons at different rates in a manner to compress the fluid, anddischarge the same through the outlet port, and said means comprisingcranks having different throws and different angular advances andrespectively operatively connected to the pistons, and means for drivingthe cranks at the same speed.

3. A pump `having a cylinder provided with inlet and outlet ports,opposed pistons reciprocably mounted in the cylinder for controllingsaid ports, means for reciprocating the opposed pistons in the cylinderin a manner that the pistons cooperate with one another to draw fluidinto the cylinder therebetween during the interval the intake port isopen and to compress the iluid and open the' outlet port, said meanscomprising a pair of cranks having diierent throws with the throw of onecrank in advance of the throw of the other and means respectivelyoperatively connecting the cranlm to the pistons.

4. A pump having a cylinder provided with inlet and outlet ports,opposed pistonsreciprocably mounted in the cylinder for controlling saidports, means for reciprocating the opposed pistonsin the cylinder in amanner that the pistons cooperate with one another to draw fluid intothe cylinder therebetween during the interval the intake port is openand to compress the fluid and open. the outlet port, said meanscomprising a pair of cranks driven at the same speed and havingdifferent throws, the throw of one crank being in advance of the throwof the other and means respectively operatively connecting the cranks tothe pistons.

5. A pump having a cylinder provided with inlet and outlet ports,opposed pistons reciprocably mounted in the cylinder for controllingsaid ports, means for reciprocatingl the opposed pistonsvin the cylinderin a manner that the pistons cooperate with one anotherto draw fluidinto the cylinder 'therebetween during the interval the intake port isopen and to compress the fluid and open .the outlet port,- said .meanscomprising a pair of cranks driven at the same speed and con-` GEORGE n.LYON.

